Tag Archives: scale out

Exploring the venerable NFS Ganesha

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As TrueNAS® SCALE approaches its General Availability date in less than 10 days time, one of the technology pieces I am extremely excited about in TrueNAS® SCALE is the NFS Ganesha server. It is still early days to see the full prowess of NFS Ganesha in TrueNAS® SCALE, but the potential of Ganesha’s capabilities in iXsystems™ new scale-out storage technology is very, very promising.

NFS Ganesha

I love Network File System (NFS). It was one of the main reasons I was so attracted to Sun Microsystems® SunOS in the first place. 6 months before I graduated, I took a Unix systems programming course in C in the university. The labs were on Sun 3/60 workstations. Coming from a background of a VAX/VMS system administrator in the school’s lab, Unix became a revelation for me. It completely (and blissfully) opened my eyes to open technology, and NFS was the main catalyst. Till this day, my devotion to Unix remained sacrosanct because of the NFS spark aeons ago.

I don’t know NFS Ganesha. I knew of its existence for almost a decade, but I have never used it. Most of the NFS daemons/servers I worked with were kernel NFS, and these included NFS services in Sun SunOS/Solaris, several Linux flavours – Red Hat®, SuSE®, Ubuntu, BSD variants in FreeBSD and MacOS, the older Unices of the 90s – HP-UX, Ultrix, AIX and Irix along with SCO Unix and Microsoft® Xenix,  NetApp® ONTAP™, EMC® Isilon (very briefly), Hitachi® HNAS (née BlueArc) and of course, in these past 5-6 years FreeNAS®/TrueNAS™.

So, as TrueNAS® SCALE beckons, I took to this weekend to learn a bit about NFS Ganesha. Here are what I have learned.

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What If – The other side of Storage FUDs

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Streaming on Disney+ now is Marvel Studios’ What If…? animated TV series. In the first episode, Peggy Carter, instead of Steve Rogers, took the super soldier serum and became the first Avenger. The TV series explores alternatives and possibilities of what we may have considered as precept and the order of things.

As storage practitioners, we are often faced with certain “dogmatic” arguments which were often a mix of measured actuality and marketing magic – aka FUD (fear, uncertainty, doubt). Time and again, we are thrown a curve ball, like “Oh, your competitor can do this. Can you?” Suddenly you are feeling pinned to a corner, and the pressure to defend your turf rises. You fumbled; You have no answer; Game over!

I experienced these hearty objections many times over. The best experience was one particular meeting I had during my early days with NetApp® in 2000. I was only 1-2 months with the company, still wet between the ears with the technology. I was pitching the SnapMirror® to Ericsson Malaysia when the Scandinavian manager said, “I think you are lying!“. I was lost without a response. I fumbled spectacularly although I couldn’t remember if we won or lost that opportunity.

Here are a few I often encountered. Let’s play the game of What If …?

What If …?

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Glusterific!

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A conversation with a storage executive last week brought up Gluster, a clustered file system I have not explored in many years. I had one interaction months before its acquisition by RedHat® in 2011.

I remembered the Gluster demo at Jaring over a video call, because I was the lead consultant pitching the scale-out NAS solution. It did not go well, and there were “bugs” which made the Head of IT flinched in her seat. Despite Jaring being Malaysia’s technology trailblazer, the impression of Gluster was forgettable. I stayed on the GlusterFS architecture a little while and then it dropped off my radar.

Gluster Logo Scale Out NAS

Gluster Scale Out NAS

But after the conversation last week, I am elated to revive my interest in Gluster, knowing that something big and impressive in coming into the fore very soon. Studying the architecture (again!), there are 2 parts of Gluster which excite me. One is the Brick and the other is the lack of a Metadata service.

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Cohesity SpanFS – a foundational shift

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[Preamble: I was a delegate of Storage Field Day 15 from Mar 7-9, 2018. My expenses, travel and accommodation were paid for by GestaltIT, the organizer and I was not obligated to blog or promote the technologies presented at this event. The content of this blog is of my own opinions and views]

Cohesity SpanFS impressed me. Their filesystem was designed from ground up to meet the demands of the voluminous cloud-scale data, and yes, the sheer magnitude of data everywhere needs to be managed.

We all know that primary data is always the more important piece of data landscape but there is a growing need to address the secondary data segment as well.

Like a floating iceberg, the piece that is sticking out is the more important primary data but the larger piece beneath the surface of the water, which is the secondary data, is becoming more valuable. Applications such as file shares, archiving, backup, test and development, and analytics and insights are maturing as the foundational data management frameworks and fast becoming the bedrock of businesses.

The ability of businesses to bounce back after a disaster; the relentless testing of large data sets to develop new competitive advantage for businesses; the affirmations and the insights of analyzing data to reduce risks in decision making; all these are the powerful back engine applicability that thrust businesses forward. Even the ability to search for the right information in a sea of data for regulatory and compliance reasons is part of the organization’s data management application.

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Solid in the Fire

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December 22 2015: I kept this blog in draft for 6 months. Now I am releasing it as NetApp acquires Solidfire.

真金不怕紅爐火

The above is an old Chinese adage which means “True Gold fears no Fire“. That is how I would describe my revisited view and assessment of SolidFire, a high performance All-Flash array vendor which is starting to make its presence felt in South Asia.

I first blogged about SolidFire 3 years ago, and I have been following the company closely as more and more All-Flash array players entered the market over the 3 years. Many rode on the hype and momentum of flash storage, and as a result, muddied and convoluted the storage infrastructure market understanding. It seems to me spin marketing ruled the day and users could not make a difference between vendor A and vendor B, and C and D, and so on….

I have been often asked, which is the best All-Flash array today. I have always hesitated to say which is the best because there aren’t much to say, except for 2-3 well entrenched vendors. Pure Storage and EMC XtremIO come to mind but the one that had stayed under the enterprise storage radar was SolidFire, until now.

SolidFire Logo

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The reverse wars – DAS vs NAS vs SAN

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It has been quite an interesting 2 decades.

In the beginning (starting in the early to mid-90s), SAN (Storage Area Network) was the dominant architecture. DAS (Direct Attached Storage) was on the wane as the channel-like throughput of Fibre Channel protocol coupled by the million-device addressing of FC obliterated parallel SCSI, which was only able to handle 16 devices and throughput up to 80 (later on 160 and 320) MB/sec.

NAS, defined by CIFS/SMB and NFS protocols – was happily chugging along the 100 Mbit/sec network, and occasionally getting sucked into the arguments about why SAN was better than NAS. I was already heavily dipped into NFS, because I was pretty much a SunOS/Solaris bigot back then.

When I joined NetApp in Malaysia in 2000, that NAS-SAN wars were going on, waiting for me. NetApp (or Network Appliance as it was known then) was trying to grow beyond its dot-com roots, into the enterprise space and guys like EMC and HDS were frequently trying to put NetApp down.

“It’s a toy…”  was the most common jibe I got in regular engagements until EMC suddenly decided to attack Network Appliance directly with their EMC CLARiiON IP4700. EMC guys would fondly remember this as the “NetApp killer“. Continue reading →

Hail Hydra!

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The last of the Storage Field Day 6 on November 7th took me and the other delegates to NEC. There was an obvious, yet eerie silence among everyone about this visit. NEC? Are you kidding me?

NEC isn’t exactly THE exciting storage company in the Silicon Valley, yet I was pleasantly surprised with their HydraStorprowess. It is indeed quite a beast, with published numbers of backup throughput of 4PB/hour, and scales to 100PB of capacity. Most impressive indeed, and HydraStor deserves this blogger’s honourable architectural dissection.

HydraStor is NEC’s grid-based, scale-out storage platform with an object storage backend. The technology, powered by the DynamicStor ™ software, a distributed file system laid over the HydraStor grid architecture. At the same time, it has the DataRedux™ technology that provides the global in-line deduplication as the HydraStor ingests data for data protection, replication, archiving and WORM purposes. It is a massive data consolidation platform, storing gazillion loads of data (100PB you say?) for short-term and long-term retention and recovery.

The architecture is indeed solid, and its data availability goes beyond traditional RAID-level resiliency. HydraStor employs their proprietary erasure coding, called Distributed Resilient Data™. The resiliency knob can be configured to withstand 6 concurrent disks or nodes failure, but by default configured with a resiliency level of 3.

We can quickly deduce that DynamicStor™, DataRedux™ and Distributed Resilient Data™ are the technology pillars of HydraStor. How do they work, and how do they work together?

Let’s look a bit deeper into the HydraStor architecture.

HydraStor is made up of 2 types of nodes:

  • Accelerator Nodes
  • Storage Nodes

The Accelerator Nodes (AN) are the access nodes. They interface with the HydraStor front end, which could be CIFS, NFS or OST (Open Storage Technology). The AN nodes chunks the in-coming data and performs in-line deduplication at a very high speed. It can reach speed of 300TB/hour, which is blazingly fast!

The AN nodes also runs DynamicStor™, handling the performance heavy-lifting portion of HydraStor. The chunked data from the AN nodes are then passed on to the Storage Nodes (SN), where they are further “deduped in-line” to determined if the chunks are unique or not. It is a two-step inline deduplication process. Below is a diagram showing the ANs built above the SNs in the HydraStor grid architecture.

NEC AN & SN grid architecture

 

The HydraStor grid architecture is also a very scalable architecture, allow the dynamic scale-in and scale-out of both ANs and SNs. AN nodes and SN nodes can be added or removed into the system, auto-configuring and auto-optimizing while everything stays online. This capability further strengthens the reliability and the resiliency of the HydraStor.

NEC Hydrastor dynamic topology

Moving on to DataRedux™. DataRedux™ is HydraStor’s global in-line data deduplication technology. It performs dedupe at the sub-file level, with variable length window. This is performed at the AN nodes and the SN nodes level,chunking and creating unique hash values. All unique chunks are further compressed with a modified LZ compression algorithm, shrinking the data to its optimized footprint on the disk storage. To maintain the global in-line deduplication, the hash table is available across the HydraStor cluster.

NEC Deduplication & Compression

The unique data chunk resulting from deduplication and compression are then written to disks using the configured Distributed Resilient Data™ (DRD) algorithm, at its set resiliency level.

At the junction of DRD, with erasure coding parity, the data is broken up into multiples of fragments and assigned a parity to a grouping of fragments. If the resiliency level is set to 3 (the default), the data is broken into 12 pieces, 9 data fragments + 3 parity fragments. The 3 parity fragments corresponds to the resiliency level of 3. See diagram below of the 12 fragments spread across a group of selected disks in the storage pool of the Storage Nodes.

NEC DRD erasure coding on Storage Nodes

 

If the HydraStor experiences a failure in the disks or nodes, and has resulted in the loss of a fragment or fragments, the DRD self-healing function will auto-rebuild and auto-reconfigure the recovered fragments in another set of disks, maintaining the level of 3 parities.

The resiliency level, as mentioned earlier, can be set up to 6, boosting the HydraStor survival factor of 6 disks or nodes failure in the grid. See below of how the autonomous DRD recovery works:

NEC Autonomous Data recovery

Despite lacking the razzle dazzle of most Silicon Valley storage startups and upstarts, credit be given where credit is due. NEC HydraStor is indeed a strong show stopper.

However, in a market that is as fickle as storage, deduplication solutions such as HydraStor, EMC Data Domain, and HP StoreOnce, are being superceded by Copy Data Management technology, touted by Actifio. It was rumoured that EMC restructured their entire BURA (Backup Recovery Archive) division to DPAD (Data Protection and Availability Division) to go after the burgeoning copy data management market.

It would be good if NEC can take notice and turn their HydraStor “supertanker” towards the Copy Data Management market. That would be something special to savour.

P/S: NEC. Sorry about the title. I just couldn’t resist it 😉

Praying to the hypervisor God

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I was reading a great article by Frank Denneman about storage intelligence moving up the stack. It was pretty much in line with what I have been observing in the past 18 months or so, about the storage pendulum having swung back to DAS (direct attached storage). To be more precise, the DAS form factor I am referring to are physical server hardware that houses many disk drives.

Like it or not, the hypervisor has become the center of the universe in the IT space. VMware has become the indomitable force in the hypervisor technology, with Microsoft Hyper-V playing catch-up. The seismic shift of these 2 hypervisor technologies are leading storage vendors to place them on to the altar and revering them as deities. The others, with the likes of Xen and KVM, and to lesser extent Solaris Containers aren’t really worth mentioning.

This shift, as the pendulum swings from networked storage back to internal “direct-attached” storage are dictated by 4 main technology factors:

  • The x86 server architecture
  • Software-defined
  • Scale-out architecture
  • Flash-based storage technology

Anyone remember Thumper? Not the Disney character from the Bambi movie!

thumper-bambi-cartoon-character

When the SunFire X4500 (aka Thumper) was first released in (intermission: checking Wiki for the right year) in 2006, I felt that significant wound inflicted in the networked storage industry. Instead of the usual 4-8 hard disk drives in the all the industry servers at the time, the X4500 4U chassis housed 48 hard disk drives. The design and architecture were so astounding to me, I even went and bought a 1U SunFire X4150 for my personal server collection. Such was my adoration for Sun’s technology at the time.

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Run free … Symantec FileStore

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It has been a rough and tough 3 weeks and I missed writing my blog. Last week, the toughest of the 3, was my CompTIA Storage+ training to Symantec SEs in Malaysia. They were a great crowd, and I loved it but I was really tired after that.

One exciting news during that week was the ouster of long time employee, and CEO of Symantec, Enrique Salem and replacing him with Steve Bennett, their Chairman. The news of that unfortunate event can be read from here and here. And almost hours after that, the calls to break up the Veritas portion of Symantec came up and putting pressure on the board of directors in Symantec to either spin-off the entity or sell it off.

To be fair, many observers, including me, believed that the marriage between Symantec and Veritas in 2005 wasn’t really what you would call a “match made in heaven”. It was more like strange bedfellows to me. And there was an internal joke (one that I could not verify) about the Veritas CEO, Gary Bloom’s promise to the Veritas board when he joined them from Oracle in 2000.

It went like this:

“Gary Bloom promised the Veritas board of directors in 2000 that he would be able to bring Veritas to a USD$5 billion dollar company in 5 years time. Nearing the end of the 5 years in 2005, Gary fulfilled his promise by merging with Symantec, instantly making Veritas a USD$5 billion dollar company.”

Note: This is just an inside joke which I heard from a Veritas friend back in 2005, and by no means put Gary Bloom in a bad light. If I did, I apologize.

But back to the present. Our class last week brought up the subject of Symantec FileStore. When it first came out in October 2009, I thought it was an interesting solution. For once, I thought there was something could “out filesystem” NetApp’s ONTAP and WAFL, because Veritas had one of the best scale-out, clustered file systems. They just haven’t figured out the front end protocols yet, where NAS and iSCSI reigned. Veritas File System (VxFS) and Veritas Cluster File System as part of Veritas Cluster Server (VCS) was mature and proven in the enterprise. Along with Veritas Volume Manager (VxVM), this was perhaps THE best file system/volume management suite around. Mind you, ZFS hasn’t reached the level of prominence yet at that time.

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